Most distinguishing features: Highly magnetic. Habit and colour are also indicators.
Industrial/economical uses: Mined for iron. Crushed magnetite also been used as aggregate to make high-density concrete for specialized applications, such as nuclear reactors.
Most distinguishing features: Colour and habit are best indicators.
Industrial/economical uses: Used in the electronics industry in the manufacture of capacitors, transistors, insulators and certain window types. Also used as a filler in building materials.